I thought this might be an interesting discussion.

For instance I lost 10 soft pounds give or take over the summer by accident changing absolutely nothing other than intentionally getting a sane, but significant amount of sun. Same food, same training same activity level.

It is now several weeks since the sun went south, my tan is almost gone and the fat is coming back, again changing absolutely nothing else. (I wish I would've got some picks)

I don't care because I know where it will stop.

I remember reading something years ago that discussed the anabolic/androgenic effects of natural sunlight and I thought this summer's experience was pretty interesting.

Are you bringing this up so that we can talk about seratonin levels & it's effects on body fat percentage? We could do that.

Or are you bringing it up for the "latent" exercise levels, as Tiznut mentions?

Part of this is Vit-D, take 2000-3000iu per day. Those with darker skin make less Vit-D from sunlight exposure.

Personally Im definitely more lean in the summer, although its hard to tell what this is due too.

I defnintely do more exercise in the summer in terms of throwing a ball around, walking more places etc.

I do certainly feel better somehow when the suns out more.

Well as we all know; the winter is 'prone' to bring on feelings of sluggishness and depression...but that's in 'normal' people. People like us that are training and are active have higher endorphin levels and shouldn't be AS susceptible to this.


In the summer, I'm more apt to hang outside as well. Walking the dog, hitting the bag, going for longer walks, going to the beach etc etc...

In the winter, the most activity I get outside is from letting my dog run about; and shoveling (which is a killer workout depending on snowfall). But I do feel a bit more lethargic when it's a non-training day. I gotta use my exercise bike a bit more...

you're getting ready for hibernation yogi!!

This started because I wanted the health benefits of sunlight regardless of what the idiotic medical establishment tries to tell us.

I doubt if I weighed myself 3 times all summer. I noticed by July that I was getting leaner. I thought I was imagining it at first. I weighed myself at the end of August and I was in the mid 230's even though I was getting stronger and my training was going great.

If anything I ate a bit more and got less overall exercise than during the winter when I was consistently walking like 15 miles a week up and down stairs through snow putting fliers on houses. I did that less during the summer because I had more business and less time to do fliers which meant I sat in front of computers more.

I'm convinced the sun was a major contributor if not THE factor in my losing that soft weight even though I did absolutely nothing to try and make that happen.

I didn't get real lean, but it was visibly noticeable and now I'm softening up a little with the only difference being no sun.

I have absolutely no evidence to back this up but tanned skin does look noticeably 'tighter' alomst than untanned skin.

Tiri, a question-

Did you sleep better during the summer? What I'm getting at is the body uses the sun to shut off melatonin production and keep a regular circadian rhythm.

Sleep is anabolic. Although for the time I can't pinpoint the reasons for fat loss, I agree that sun exposure helps. Why? I sit out and tan during the summer, and I've noted that same benefits as you, Tiri. (Tanning beds are overrated and harmful in my opinion).

The next thing I'm researching is heat and UV rays and fat storage. I'll see if I can find any correlation.

BAM! Sunlight messes with leptin.

Regulation of adipose tissue leptin secretion by alpha-melanocyte-stimulating hormone and agouti-related protein: further evidence of an interaction between leptin and the melanocortin signalling system

http://jme.endocrinology-journ...

In Arnold: The Education of a Bodybuilder, the Oak mentions laying outside in the sun in order to "burn off that extra layer of fat just beneath the skin" (or something to that effect; I don't have the book on me so I can't get an exact quote).

I had a little chuckle when I read that, but maybe he (and Tirib) are on to something.

I never had guys in the gym ask me if I was getting ready for a contest (it's a weird question as I don't remotely have the genetics) until getting a good tan, but after the tan have been asked that at least 8 or 10 times in the last few months.

It has been easier staying lean while well-tanned also.

The tan is from natural sun and Melanotan II.

It is known that Vitamin D aids fat loss. Whether there are other fat-loss benefits to the sun, I don't know.

Okay, after much researching, this is what I've come to.

Melanin is produced by 2 two ways. Melanogenesis is one, and that is when melanocytes produce melanin. The other is the intriguing one. Melanin production also comes from Adrenocorticotropic hormone.

My theory is this: When tanning, ACTH is produced in the pituitary gland. The same process that produces ACTH also produces several other hormones, one of which is of monument importance to fat loss.

Lipotropin is produced along with ACTH and others (like β-endorphin which makes you feel good as you tan, at least I do).

Lipotropin stimulates melanocytes to produce melanin, but it also performs LIPOLYSIS and STEROIDOGENESIS!

That's right, lipolysis. Tan and burn that fat away.

I need to get outside more... and not just because my German/Swedish/Austrian heritage leaves me near-transparent by the end of Winter.

I get zero, and I mean literally zero, minutes of sun exposure during the workweek. I'll need to put some effort into remedying that situation, given what I've been reading lately.